Tapping machine



Patented May 4, 1937 UNITED STATES ATENT OFFICE 20 Claims.

This invention relates to machines designed to perform tapping operations in a workpiece; and the object of the invention is to provide a machine of the class described employing a footactuated lever or treadle for actuating the tapping attachment of the machine to move the same in the direction of the work or workpiece, and especially in the provision of a substantially balanced treadle weight to not only balance the tapping attachment and associated parts, but also sufficient to move said parts upwardly out of engagement with the workpiece after performing a tapping operation, and this structure further provides very light treadle operation which relieves the labor or fatigue in the manual operation of the machine to a large degree; a further object being to provide a resilient coupling between the foot lever and the operating rods coupled with the tapping attachment whereby movement is imparted to the attachment through said yieldable or resilient coupling; a. further object being to provide a yielding buffer checking sudden upward movement of the lever when the foot is released therefrom; a further object being to provide adjustable means for checking the downward movement of the foot lever as well as independent adjustable means for limiting or gaging the downward movement of the tapping attachment including the tap supported thereby; a further object being to provide antifrictional means for mounting, bracing and guiding the tapping attachment and associated parts in the standard of the machine; a further object being to provide means for relieving stresses or strains on the quill of the machine; a still further object being to provide a workpiece stripping device including an adjustable strip or plate, said device being adjustable on the frame of the machine and relatively to an adiO justable bed plate or table; and with these and other objects in view, the invention consists in a machine of the class defined which is simple and economical in construction and which is constructed as more fully hereinafter described and claimed.

The invention is fully disclosed in the following specification, of which the accompanying drawing forms a part, in which the separate parts of my improvement are designated by suitable reference characters in each of the views, and in which:

Fig. l is a side and sectional view of a machine made according to my invention with parts of the construction broken away; and,

Fig. 2 is a partial section on the line 22 of Fig. 1.

In carrying my invention into effect, I provide a base 5 consisting of a channeled base plate 6 having upwardly directed side brackets I terminating at their upper end in a split bearing 8 which may be clamped by means of a bolt indicated at 9 upon the lower end of a vertical column or standard I0 of the machine, the same being in the form of a tube in the construction shown. Secured upon the upper end of the column I0 is an operating or driving head I l which includes the usual mechanism for actuating the spindle I 2 which extends below the lower end of the quill l3. The head II is more or less of conventional construction such as employed in certain types of drill presses, and for this reason, the details of the head are not shown nor described as they formed no direct part of this invention, and any particular type of drive for the spindle l2 may be provided.

The head II in the construction shown has an electric motor l4 supported at one side thereof. On the shaft of the motor are a number of pulleys l5, around which a belt it passes, said belt passing around corresponding pulleys on the shaft ii, the pulleys being arranged in a hood or housing I 8. This construction is to provide the conventional variable speed drive of the shaft l7. Clamped to the lower end portion of the quill I3 is an adapter l9, to the lower surface of which is detachably supported a tapping attachment 20 which may be of any described type and construction. In practice, the adapter I9 as well as the various attachments 20 employed may be so constructed as to have the adapter constitute a universal mounting for different kinds and classes of tapping attachments.

At 2!, I have shown a tap supported in connection with the attachment and projecting below the lower surface thereof. At 22, I have shown the bed plate or workpiece supporting table which is longitudinally and circumferentially adjustable upon the column IE! and clamped in different positions of adjustment by means of the hand screw lever 23. At 24, I have shown a stripping device which is also vertically and circumferentially adjustable upon the column ill and has a clamping lever 25 similar to the lever 23 for securing the device in different positions of adjustment. A stripping plate or arm 26 is adjustably mounted in connection with the device by means of screws 27 operating in an elongated aperture 28 in said device 24 to adjust the position of the plate 26 with respect to the tap 2| to compensate for workpieces of various kinds and classes.

Mounted in one side of the adapter l9 and projecting upwardly at one side of the head II is a stop rod 29 which is threaded to receive adjusting nuts 30 which control and regulate, or, in other words, limit the downward movement of the attachment 20 or the tap 2| with respect to a suitable workpiece. The rod 29 is guided in the head II by passing through suitable bearings 3| projecting outwardly from the head II. Coupled with the upper end of the rod 23 is a torsion spring 32 which is also secured to the head LII as indicated at 33. This spring serves to eliminate or take up the torsional stresses or strains to which the quill 13 may be subjected in the operation of the machine. In this connection, it will be understood'that the head I I is modified in its construction to a slight degree in adapting the same for use as a tapping machine, and in. lieu of this modification, the desirability of employing the torsional spring 32 is regarded as practical.

Mounted in the side brackets or plates :7 .of the base 5 at the rear portion thereof is a shaft 34 on which is preferably arranged a ball bearing 35 to provide ananti-frictional pivot mounting of the treadle or lever 36 which extends forwardly between the plate 1 and terminates at its free end in a footpiece 3?. The lever 36 is angular in form and includes .a rearwardly extending arm 38 upon which is mounted an upwardly extending .rod .39 for retaining a plurality of ring- ,like weights All upon the upper surface of the arm .38. The arm.38 of the lever 38 is provided withan upwardly directed stop surface 41, near .the pivot 3t.

Freely extending through the arm 38 is a rod dlsupportedin connection with the base plate 5 .as seen, and the upper end of which .is threaded to receive a milled stop adjusting nut 43 and a wing-.likenut 44. The lever3i adjacent the pivot 3.4 isprovided with an angularly extending seat 45 .in connection with which .a buffer rod 16 is adapted to operate in checking orcushioning the upward movement of the lever 36 in the sudden removal .of .the foot therefrom. The rod M3 is mounted in asleeve 4'! adjustably mounted in the head .8 in an angular position substantially as shownin the drawing. A-set screw $8 is employed-to retain thersleeve 41in different positions of adjustment.

The .rod 46 constitutes a plunger which is adapted to operate upon-a coil springAQarranged in the sleeve 4.! and .arounda guide rod or bolt v5i] which is coupled with the upper end of the plunger 46 and extends through the outer end of the sleeve. 'The rod 5.0 has .a nut or head 5! which limits the downward movement of'the plunger 46. Mounted :in the central or corner portion of the lever :36 is va transverse .pin or bolt ,52 which forms a pivot for the lower end of .an eye-bolt 53. Asleeve nut 54 is .adjustably mounted on the bolt .53 and serves to raise and lower the position .of the plunger tube .55 on the eye-bolt .53. Said =bolt extends into the plunger tube .55 to provide .a bearing and guide therefor, but said tube is movable longitudinally of said bolt.

.A .nut 56 is adjustably mounted .on the sleeve nut :54 and secured .to this .nut is .a coil spring 51, the upper end of which engagesaswivel L58 whichseats upon .a collar .59 secured to the tube v55. The spring 51 operates .to .normallysupport the .tube upon the upper surface of the sleeve nut-.54. fI.'he.plunger.55.extends upwardlythrough the column in, and an eye-bolt or pin .60 .is securedzin the upperendthereof, to which is pivoted the lower yoke-shaped end of a plunger body 3! as seen at 62. .Rotatably mounted-on the upper and lowerend portions of the body .6! are pairs of guide and bearing wheels 63 which serve to freely or anti-frictionally guide and brace the body 61 in .its movement longitudinally .of the column [0.

.Centrally of the body BI is an enlargement 64 to which is secured a rod 65 which passes outwardly through an elongated opening 56 formed in the column It]. The free end 61 of the rod 35 is supported in the adapter l9 as clearly seen. A supplemental plunger 68 may be coupled with the upper end of the body 6! as indicated in dotted lines in Fig. 1, and this plunger extends upwardly beyond the head H and is provided 'with a seat 69 upon which supplemental counterbalance weights 10 may be supported, if desired. The parts 68, 69 and 10 are indicated in dotted lines, solely for the reason that they are not an essential part of the machine and may or may not be employed.

The adjustment of the sleeve nut 54 will control and regulate the position of the .quill l3 and tapping attachment 20 with respect .to the head H, that is to say, the position to be assumed by said parts when at the upper end of the stroke. This adjustment will also regulate the height of the treadle or footlever 36 to suit the operator. After this adjustment has been arranged to suit the operator and the work upon which the tapping is to be performed, and after other adjustment of the bed plate 22 and stripping device 24 is made, the buffer plunger 46 or its supporting sleeve 4.! will be adjusted so as to provide the desired buffer action against the treadle when released to check the upward movement .of the tapping attachment 23 by the spring 5-! and weights 4!]. As long as the same tapping attachment is employed with a tap .2! of substantially the same size and weight, .no further adjustment need be made with respect to the treadle and parts above referred to, especially when tapping the same general class of work. The weights 43 may be changed .to compensate for vany change made in the machine, without-changing thetreadle or lever adjustment. With different workpieces, the table 22and stripping device Z i alone may be adjusted without interfering with the treadle or foot lever and tapping-attachment adjustment.

In the upward movement of the attachment out of engagement with a workpiece, the weights 40 act through the lever 36, the bolt 53 .and the sleeve nut 54 to positively engage the lower end of the tube 55 in performing this operation.

With different workpieces, the nuts 33 will be adjusted to gage the downward movement of the tap.2l into the workpiece, and when this adjustment is made, the nut 43 is adjusted to effect a stop .of the lever 36 at a point slightly beyond thatof the adjustment of the nuts 38 so that the lever has a slight travel beyond the travel .necessary to bring the nut .30 into-engagement with the bearing guides .31 which also function as stops limiting the downward movement of the rod 29. It is understood in thisconnection, that the independent movement of the lever is possiblethrough the spring 51. The nut 43 operates to check any unnecessary strain or stress on the springiil.

.After the various adjustments and balancing of the machine have been made, the machine is ready for operation. The switch it of the motor M may be moved to .put the motor into operation, which, in turn, will cause the tool 2| to be operated through the attachment .2!) and the driven spin-dle l2 which is-coupled with the attachment or the drive mechanism of the attachment as in other devices of this kind. The workpiece is now placed upon the bed plate or table 22, and the operator depresses the treadle or foot lever 36, in which operation, the plunger lease the pressure on the treadle.

body carrying the attachment 20 and associated parts is moved downwardly, the plunger tube 55 being drawn downwardly through the spring 51 which forms a yielding or resilient coupling between the eye bolt 53 and the plunger tube 55, thus eliminating a positive mechanical movement of the tap 25 into the work, but on the other hand, provides a yieldable feed of the tap into the work. The weight of the tapping attachment and associated parts including the weight Til if employed, will aid in the downward movement of the tap the instant that slight pressure is applied to the treadle, and this movement is against the action of the counterbalance weights Ml. When the tap 2| reaches the limit of its downward stroke, which is gaged by the stop nuts 36, the treadle 36 will be released and the extended spring 51 will contract to bring the upper end of the sleeve nut 54 into engagement with the plunger tube 55, and the balance weights 45 will operate to move the tap 2|, attachment 20 and associated parts upwardly, and this upward movement is checked by the buffer rod or plunger 46.

At this time, it is well to bear in mind that the tapping attachment 2!! has a reverse drive as in devices of this kind commonly known, which feeds the tap out of the workpiece, and a strip or plate may be utilized by the operator, if desired, especially in tapping relatively light work, to support the work against the action of the tapper in its upward movement. Suificient clearance will be provided at all times between the adapter I9 and head II to provide for a movement of the tap 2| out of engagement with the workpiece when supported on the stripper device as well as to compensate for the upward travel of the plunger beyond a point of normal balance.

In the above described operation of releasing the pressure on the treadle 36 to permit upward movement of the attachment 20 including the tap 2|, this operation may be performed by sudden removal of the foot from the treadle, or in other cases, by simply raising the foot to gradually re- The mode of this operation will be gaged and regulated by the operator of the machine to care for the tapping of workpieces of various kinds and classes.

A machine of the character described is simple and economical in construction, as well as heat and finished in its appearance; and by arranging the plunger rod 55 and its associated parts within a tubular column or within the boundaries of a standard, no interference is made to the rotatable as well as longitudinal adjustment of the bed plate and stripping device. At the same time, protection is afforded to the plunger tube, plunger body and associated parts that are disposed within the standard or column to.

Furthermore, a machine of the character defined will speed up the tapping of workpieces and will perform the desired tapping operations in a substantially fool-proof manner, which will eii'ect a saving in the breakage or destruction of taps as commonly experienced, especially by reason of the fact that the tap is moved or fed into the workpiece through a yieldable or resilient coupling which will not permit the forcing or jamming of the tap into the workpiece.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A machine of the class described comprising a base, a standard, a tool operating attachment, means at the upper end portion of the standard for supporting, guiding and operating said attachment to rotate a tool supported therein, and manually operated means including a yielding coupling and a plunger arranged longitudinally of said standard for moving said attachment and the tool supported therein in the direction of a workpiece supported in the machine, and means in operative engagement with said last named means for counterbalancing the weight of said attachment and associated parts to move the attachment away from the work when said manually actuated means is released.

2. In a tappingmachine employing a tool operating head, a tapping attachment movable with respect to said head, means at one side of and in spaced relation to said attachment for supporting and guiding the attachment in its movement relatively to said head and toward and from a workpiece in performing a tapping operation, and said means involving a plunger having spaced anti-frictional means for supporting and guiding the plunger in its movement with respect to a support on the machine.

3. In a machine of the class described employing a tapping attachment movable toward and from a workpiece, manually actuated means including counterbalancing means for operating said attachment whereby in each cycle of opera-- tion the attachment moves by gravity into engagement with the workpiece and is fed into the workpiece through the added action or" a yieldable coupling to eliminate stress or strain on the tool in performing a tapping operation and further whereby, in the reverse movement of the attachment, the tool thereof is positively moved out of the workpiece by the aid of said counterbalancing means.

4. In a tapping machine employing a tapping attachment movable toward and from a work piece supported in the machine, means for controlling the movement or" the attachment toward and from a workpiece comprising a treadle pivotally supported in the machine and in operative engagement with said attachment, means on the treadle for counterbalancing said attachment and associated parts to move the attachment upwardly out of engagement with a workpiece when the treadle pressure is released, and a buffer in operative engagement with the treadle to check the action of said counterbalancing means and i to substantially balance the same when the attachment is in normal position.

5. In a tapping machine employing a tapping attachment movable toward and from a workpiece supported in the machine, means for controlling the movement of the attachment toward and from a workpiece comprising a treadle pivotally supported in the machine and in operative engagement with said attachment, means on the treadle for counterbalancing said attachment and associated parts to move the attachment upwardly out of engagement with a workpiece when the treadle pressure is released, a bufier in operative engagement with the treadle to check the action of said counterbalancing means and to substantially balance the same when the attachment is in normal position, means for operating and guiding the attachment in its movement in the machine, and tensional means compensating for the torsional stresses to which the last named means is subjected in the operation of said at tachment.

6. In a machine of the class described employing a tapping attachment with means for operating a tool supported in the attachment,

means for moving the attachment toward and from a workpiece, said means involving a plunger and a treadle, said treadle having a yieldable coupling with the plunger to eliminate the stress and strain on a tool in the operation of feeding the same into a workpiece, and said plunger including adjustable means for increasing or decreasing the length thereof.

7. In a tapping machine employing a tapping attachment in connection with which a tap is supported, means for rotating said tap through the attachment, a workpiece support adjustable relatively to said attachment, means for supporting and guiding the attachment to permit movement thereof toward and from a workpiece, means for normally supporting the attachment 'in spaced relation to the workpiece, and manually actuated means involving a yielding coupling for moving the attachment and associated parts in the direction of a workpiece to control the feed of the tool of said attachment into the workpiece in a tapping operation.

8. In a tapping machine employing a tapping attachment in connection with which a tap is supported, means for rotating said tap through the attachment, a workpiece support adjustable relatively to said attachment, means for support ing and guiding the attachment to permitmovement thereof toward and ironic. workpiece, means for normally supporting the attachment in spaced relation to the workpiece, manually actuated means involving a yielding coupling for moving the attachment and associated parts in the direction of a workpiece to control the feed of the tool of said attachment into the workpiece in a tapping operation, and adjustable means for gaging the movement of the attachment in the direction of the workpiece.

9. In a tapping machine employing a tapping attachment in connection with which a tap is supported, means for rotating said tap through the attachment, a workpiece support adjustable relatively to said attachment, means for supporting and guiding the attachment to permit movement thereof toward and from a workpiece, means for normally supporting the attachment in spaced relation to the workpiece, manually actuated means involving a yielding coupling for moving the attachment and associated parts in the direction of a workpiece to control the feed of the tool of said attachment into the workpiece in a tapping operation, adjustable means for gaging the movement of the attachment in the direction of the workpiece, and other adjustable means for limiting the movement of said manually actuated means in the operation of feeding the attachment in the direction of a workpiece.

10. In a tapping machine employing a tapping attachment in connection with which a tap is supported, means for rotating said tap through the attachment, a workpiece support adjustable relatively to said attachment, means for supporting and guiding the attachment to permit movement thereof toward and from a workpiece, means for normally supporting the attachment in spaced relation to the workpiece, manually actuated means involving a yielding coupling for moving the attachment and associated parts in the direction of a. workpiece to control the feed of the tool of said attachment into the workpiece in a tapping operation, adjustable means for gaging the movement of the attachment in the direction of the workpiece, other adjustable means in the operation of feeding the attachment in the direction of a workpiece, and said third named means serving to move theattachment away from the workpiece when said manu ally actuated means is released.

11. In a machine of the class described comprising a base, a tubular standard extending upwardly from the base, a tool operating head at the upper end of the standard, a tool operating attachment, a plunger mounted in said standard and having means therein and projecting therefrom for sup-porting and guiding the attachment in the movement of the attachment longitudinally of the standard and said head, a treadlepivotally mounted in the base of said machine, and

means involving a yieldable coupling for placing said plunger in operative engagement with the treadle whereby in the downward movement of said treadle, said attachment is fed downwardly through the action of said yieldable coupling.

'12. A machine of the class described comprising a base, a tubular standard extending upwardly from the base, a tool operating attachment, a plunger mounted in said standard and having means therein and projecting therefrom for supporting and guiding the attachment in the movement of the attachment longitudinally of the standard and said head, a treadle pivotally mounted in the base of said machine, means involving a yielding coupling for placing said plunger in operative engagement with the treadle whereby in the downward movement of said treadle, said attachment is fed downwardly through the action of said yieldable coupling, and. means in operative engagement with the treadle for moving the attachment upwardly out of engagement with a workpiece when the downward pressure on said treadle is released.

13. A machine of the class described comprising a base, a tubular standard extending upwardly from the base, a tool operating head at the upper end of the standard, a tool operating attachment, a plunger mounted in said standard and having means therein and projecting therefrom for supporting and guiding the attachment in the movement of the attachment longitudinally of the standard and said head, a treadle pivotally mounted in the base of said machine, means involving a yieldable coupling for placing said plunger in operative engagement with thetreadle whereby in the downward movement of said treadle, said attachment is fed downwardly through the action of said yieldable coupling, means in operative engagement with the treadle for moving the attachment upwardly out of engagement with a workpiece when the downward pressure on said treadle is released, and said yieldable coupling involving adjustable means for regulating the relative position of the treadle and said attachment.

14. A machine of the class described comprising a base, a tubular standard extending upwardly from the base, a tool operating head at the upper end of the standard, a tool operating attachment, a plunger mounted in said standard and having means therein and projecting therefrom for supporting and guiding the attachment in the movement of the attachment longitudinally of the standard and said head, a treadle pivotally mounted in the base of said machine,

means involving a yieldable coupling for placing b said' plunger in operative engagement with the treadle whereby in the downward movement of said treadle, said attachment is fed downwardly through the action of said yieldable coupling, means in operative engagement'with the treadle for moving the attachment upwardly out of engagement with a workpiece when the downward pressure on said treadle is released, said yieldable coupling involving adjustable means for regulating the relative position of the treadle and said attachment, and adjustable means cooperat ing with said head for gaging the movement of said attachment in the direction of a workpiece.

15. A machine of the class described comprising a base, a tubular standard extending upwardly from the base, a tool operating head at the upper end of the standard, a tool operating attachment, a plunger mounted in said standard and having means therein and projecting therefrom for supporting and guiding the attachment in the movement of the attachment longitudinally of the standard and said head, a treadle pivotally mounted in the base of said machine, means involving a yieldable coupling for placing said plunger in operative engagement with the treadle whereby in the downward movement of said treadle, said attachment is fed downwardly through the action of said yieldable coupling, means in operative engagement with the treadle for moving the attachment upwardly out of engagement with a workpiece when the downward pressure on said treadle is released, said yieldable coupling involving adjustable means for regulating the relative position of the treadle and said attachment, adjustable means cooperating with said head for gaging the movement of said attachment in the direction of a workpiece, and adjustable means for limiting the downward movement of said treadle.

16. A machine of the class described comprising a base, a tubular standard extending upwardly from the base, a tool operating head at the upper end of the standard, a tool operating attachment, a plunger mounted in said standard and having means therein and projecting therefrom for supporting and guiding the attachment in the movement of the attachment longitudinally of the standard and said head, a treadle pivotally mounted in the base of said machine,

means involving a yieldable coupling for placing said plunger in operative engagement with the treadle whereby in the downward movement of said treadle, said attachment is fed downwardly through the action of said yieldable coupling, means in operative engagement with the treadle for moving the attachment upwardly out of engagement with a workpiece when the downward pressure on said treadle is released, said yieldable coupling involving adjustable means for regulating the relative position of the treadle and said attachment, adjustable means cooperating with said head for gaging the movement of said attachment in the direction of a workpiece, adjustable means for limiting the downward movement of said treadle, and a yieldable buffer for checking the upward movement of said treadle when manual pressure thereon is released.

17. A machine of the class described comprising a base, a tubular standard extending upwardly from the base, a tool operating head at the upper end of the standard, a tool operating attachment, a plunger mounted in said standard and having means therein and projecting therefrom for supporting and guiding the attachment in the movement of the attachment longitudinally of the standard and said head, a treadle pivotally mounted in the base of said machine, means involving a yieldable coupling for placing said plunger in operative engagement with the treadle whereby in the downward movement of said treadle, said attachment is fed downwardly through the action of said yieldable coupling, means in operative engagement with the treadle for moving the attachment upwardly out of engagement with a workpiece when the downward pressure on said treadle is released, said yieldable coupling involving adjustable means for regulating the relative position of the treadle and said attachment, adjustable means cooperating with said head for gaging the movement of said attachment in the direction of a workpiece, adjustable means for limiting the downward movement of said treadle, a yieldable bufier for checking the upward movement of said treadle when manual pressure thereon is released, a stripping device adjustably mounted upon said tubular standard, and a stripper plate adjustably supported in said device.

18. In a tapping machine employing a tool operating head with a quill slidably engaging said head, an adapter mounted on said quill, a tapping attachment detachable with respect to said adapter, a tubularsupportarrangedlongitudinally of and in spaced relation to said quill, and means 1 independent of the quill and coupled with said adapter and mounted in and movable longitudinally of said support for supporting and guiding the attachment in the machine in its movement toward and from the workpiece in performing a tapping operation.

19. In a tapping machine employing a tool operating head with a quill slidably engaging said head, an adapter mounted on said quill, a tapping attachment detachable with respect to said adapter, a tubularsupport arrangedlongitudinally of and in spaced relation to said quill, means independent of the quill and coupled with said adapter and mounted in and movable longitudinally of said support for supporting and guiding the attachment in the machine in its movement toward and from the workpiece in performing a tapping operation, and means associated with said last named means for counterbalancing the attachment in the machine and for adjusting the normal position thereof with respect to said head and for providing a yieldable feed of the attachment in the direction of a workpiece supported in the machine.

20. In a tapping machine employing a tool operating head with a quill slidably engaging said head, an adapter mounted on said quill, a tapping attachment detachable with respect to said adapter, a tubular support arranged longitudinally of and in spaced relation to said quill, means independent of the quill and coupled with said adapter and mounted in and movable longitudinally of said support for supporting and guiding the attachment in the machine in its movement toward and from the workpiece in performing a tapping operation, and said means comprising a plunger having a pair of anti-frictional rollers at the upper and lower end portions thereof arranged and operating in said tubular support.

GEORGE W. EMRICK. 

